Textiles: manufacturing – Warp preparing or handling – With fluid treatment
Reexamination Certificate
2001-09-28
2004-03-16
Calvert, John J. (Department: 3765)
Textiles: manufacturing
Warp preparing or handling
With fluid treatment
C242S614000
Reexamination Certificate
active
06704980
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a warp beam of polytrimethylene terephthalate fiber yarns, a sizing method and a beaming method (that is, a method for forming an warp beam) and, particularly, to a warp beam capable of restricting the mutual stickiness of sized yarns in the warp beam, excellent in weavability and capable of providing a woven fabric having a favorable warp-wise quality.
BACKGROUND ART
When a woven fabric is produced by using synthetic fiber yarns such as polyester or polyamide as warp yarns, the warp yarns are sized with a sizing agent through a sizing machine as shown in FIG. 1, and are woven by a water jet loom or an air jet loom.
In the sizing machine shown in FIG. 1, a plurality of raw yarns
9
mounted to a creel
1
are arranged at a pitch through a reed
2
, and after being applied with a sizing agent while dipped in a bath
3
of a solution of the sizing agent, squeezed by squeezing rolls
4
to have a predetermined pickup of the sizing agent. Subsequently, the yarns
9
are dried through a first dry chamber
5
, a second dry chamber
6
and dry cylinders
7
, and taken up as a sizing beam
8
.
A stretch ratio S (%) in the sizing process is represented by a ratio of a speed of the squeeze rolls
4
to that of the dry cylinders
7
. That is, when the speed of the squeeze rolls
4
is 1.0 and the speed of the dry cylinders
7
is 0.97, S is −3%, while if that of the dry cylinder
7
varies to 1.03, S becomes +3%.
In the prior art, the stretch ratio S (%) of polyester yarns is generally adjusted to be within a range of −2%±0.5%; for example, when warp yarns of 56 dtex/24 f are sized, the stretch ratio S is selected to be approximately −2.4%. When textured yarns or others having somewhat different properties from the raw yarns, a composition and a pickup of the sizing agent and/or an amount of additives, such as a penetrant, to be added may be adjusted.
If polytrimethylene terephthalate fiber yarns are sized at the same stretch ratio S(%) as in the conventional yarns; i.e., approximately −2.4%, the yarns are excessively stretched in the dry zone of the sizing machine, resulting in problems in that yarn breakage may occur due to the wrapping of yarns or single-filaments around rollers in the sizing machine and a winding hardness of an warp beam becomes abnormally high and gradually harder with time, which in turn generates the mutual stickiness of the sized yarns to disturb the shedding motion. Thus, it was found that the deterioration of warp-wise quality such as tight warp or slack warp occurs to disable the weaving operation.
To solve the above problems, the inventors tried to reduce the pickup of sizing agent to a level lower than that usually adopted, but the mutual stickiness could not be dissolved and weavability became worse. Moreover, the inventors tried to use some sizing agents which have so lower viscosity as to hardly generate the mutual stickiness, but the mutual stickiness of warp yarns was not satisfactorily improved.
DISCLOSURE OF THE INVENTION.
The present inventors fundamentally reconsidered the sizing and beaming conditions of polytrimethylene terephthalate fiber yarns based on the novel idea of sizing technique unexpected from the prior art, and attained the present invention.
That is, the present invention is as follows:
1. A warp beam formed of a plurality of sized polytrimethylene terephthalate fiber yarns wound in a sheet form, characterized in that the hardness of the warp beam is in a range from 65 to 90 degrees.
2. A warp beam as defined by claim 1, characterized in that the warp beam is formed of polytrimethylene terephthalate fiber yarns sized so that a characteristic value Q×R satisfies the following equation:
1200
≦Q×R≦
1800
wherein Q is an initial Young's modulus (represented by cN/dtex) and R is a stretch recovery (%) at 10% elongation of the sized yarn.
3. A method for sizing polytrimethylene terephthalate fiber yarns characterized in that the yarns are fed from squeeze rolls to dry cylinders, during which a stretch-ratio S (%) is controlled between the squeeze rolls and the dry cylinders at a value in a range from −9 to −3% or from −1 to +4%.
4. A beaming method characterized in that sized yarns wound on a sizing beam obtained by the sizing method defined by claim 3 are wound on a warp beam with a tension in arrange from 0.09 to 0.22 cN/dtex.
The present invention will be described in more detail below.
In the present invention, polytrimethylene terephthalate fiber is a polyester fiber containing trimethylene terephthalate as a main repeated unit wherein the trimethylene terephthalate unit is contained at a ratio of approximately 50 mol % or more, preferably 70 mol % or more, more preferably 80 mol % or more, further more preferably 90 mol % or more. Accordingly, this fiber includes polytrimethylene terephthalate containing, as a third component, another acidic component and/or glycolic component of a total amount of less than approximately 50 mol %, preferably less than 30 mol %, more preferably less than 20 mol %, further more preferably less than 10 mol %.
The polytrimethylene terephthalate is synthesized by polymerizing terephthalic acid or a functional derivative thereof with trimethylene glycol or a functional derivative thereof in the presence of catalyst under a suitable reactive condition. In this synthesis process, one kind or more of third component may be added to the copolymerized polyester. Also, a polyester other than polytrimethylene terephthalate, such as polyethylene-terephthalate, or a polyamide may be blended with the polytrimethylene terephthalate or spun together to be a composite fiber (a sheath-core type fiber or a side-by-side type fiber).
The third component to be added includes aliphatic dicarbonic acid (oxalic acid, adipic acid or the like), cycloaliphatic dicarbdnic acid (cyclohexane dicarbonic acid or the like), aromatic dicarbonic acid (isophthalic acid, sodium sulfoisophthalic acid or the like), aliphatic glycol, (ethylene glycol, 1,2-propylene glycol, tetramethylene glycol, or the like), cycloaliphatic glycol (cyclohexane dimethanol or the like), aliphatic glycol containing aromatic group (1,4-bis(&bgr;-hydoxyethoxy) benzene or the like), polyether glycol (polyethylene glycol, polypropylene glycol or the like), aliphatic oxycarbonic acid (&ohgr;-oxycapronic acid or the like) or aromatic oxycarbonic acid (p-oxybenzoic acid or the like). Also, compounds having one or three or more ester-forming functional groups (benzoic acid, glycerin or the like) may be used provided the polymer is maintained substantially in a linear range.
The polytrimethylene terephthalate may be added with a delustering agent such as titanium dioxide, a stabilizing agent such as phosphoric acid, an ultraviolet absorbing agent such as derivative of hydroxybenzophenone, a crystallizing nucleus such as talc, a lubricant such as aerozil, an antioxidant such as derivative of hindered phenol, a flame retardant, an antistatic agent, a pigment, a fluorescent whitener, an infrared absorbing agent, and an antifoaming agent.
The polytrimethylene terephthalate fiber used in the present invention may be spun by either a normal method wherein after an undrawn yarn has been obtained at a takeup speed of approximately 1500 m/min, it is drawn at a draw ratio in a range from approximately 2 to 3.5 times, a spin-draw method wherein a spinning process is directly combined with a drawing process, or a spin-takeup method wherein a yarn spun from a spinning machine is directly taken up at a high speed of 5000 m/min or more.
The configuration of the fiber may be either uniform or irregular in thickness in the lengthwise direction, and a cross-sectional shape thereof may be circular, triangular, an L-shape, a T-shape, a Y-shape, a W-shape, an eight-lobal shape, a flat shape and a dog-bone shape. Also, the fiber may be hollow or even an indefinite shape.
According to the present invention, the polytrimethylene terephthalate fiber yarn may include t
Mizuki Hiroyuki
Yamamoto Mitsuyuki
Asahi Kasei Kabushiki Kaisha
Calvert John J.
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Muromoto Jr. Robert H.
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